I was sitting at dinner with my husband and mother-in-law at Danny’s the had an Sirius/ XM 80’s channel playing.  I was hearing songs i hadn’t heard in years like Stacey Q “We Connect” and DJ Vibes “Let Me Love You Down” and Ralph Tresvant’s “Sensitivity” and I sang right along in my head with ease.

I was a teenager in the 80’s. Song’s of the time filled my head and they continue to fill my head. The older I get the more songs  and song lyrics fill my head from current times to  music from the 70’s and 60’s. If I really stop and think about it, which I did then, it amazes me that my brains can hold all those song lyrics and notes as well as movie dialog, directions to destinations medicine names and uses etc.

The human brain contains about one billion neurons.A neuron is a nerve cell and is the building block of our nervous system. They consist of three parts and are very specialized to transmit information throughout the body.

A neuron  has three basic parts and vary in size and shape.

• The Dendrites– these are receptors which receive chemical information from neurotransmitters in the brain. The dendrites of neurons receive information from sensory receptors or other neurons. This information is then passed down to the cell body and on to the axon. Once the information has arrived at the axon, it travels down the length of the axon in the form of an electrical signal known as an action potential.
• The Axon– is a long, slender projection of a neuron which carries electrical impulses away from the neuron cell body. These are sometimes covered with a Myelin Sheath. Myelin is a fatty white substance that surrounds the axon of some nerve cells, forming an electrically insulating layer. It is essential for the proper functioning of the nervous system.
• The Cell Body- The cell body, also called the soma, is the spherical part of the neuron that contains the nucleus.

Once an electrical impulse has reached the end of an axon, the information must be transmitted across the synaptic gap to the dendrites of the adjoining neuron. They do this by chemical and electronic means.  In some cases, the electrical signal can almost instantaneously bridge the gap between the neurons and continue along its path.In other cases, Chemical neurotransmitters are needed to send the information from one neuron to the next.  While scientists have identified about 100 different neurotransmitters.  Some of these are:

• Acetylcholine –Associated with memory, muscle contractions, and learning. A lack of of this neurotransmitter is associated with Alzheimer disease.
• Dopamine – Associated with emotions and pain perception. Dopamine is strongly associated with reward mechanisms in the brain.  Drugs like cocaine, opium, heroin, and alcohol increase the levels of dopamine, as does nicotine.
• Serotonin- is an inhibitory neurotransmitter that has been found to be intimately involved in emotion and mood. helps control many functions, such as mood, appetite, and sleep. Research shows that people with depression often have lower than normal levels of serotonin. Too little can lead to depression and anxiety and feelings of suicide.
• GABA– _gamma aminobutyric acid) –
• Glutamate –the most common neurotransmitter, glutamate has many roles throughout the brain and nervous system. Glutamate is an excitatory transmitter: when it is released it increases the chance that the neuron will fire. This enhances the electrical flow among brain cells required for normal function and plays an important role during early brain development. It may also assist in learning and memory. Problems in making or using glutamate have been linked to many mental disorders, including autism, obsessive compulsive disorder (OCD), schizophrenia, and depression.
• norepinephrine -As a neurotransmitter in the central nervous system, norepinephrine increases alertness and arousal, and speeds reaction time.
• Ephedrine- Epinephrine also known as adrenaline is a neurotransmitter and hormone essential to metabolism. It regulates attention, mental focus, arousal, and cognition. It also inhibits insulin excretion and raises the amounts of fatty acids in the blood. Epinephrine is made from norepinephrine and is released from the adrenal glands. Low levels have been can result in fatigue, lack of focus, and difficulty losing weight. High levels have been linked to sleep problems, anxiety and ADHD.

.What is really the capacity of the human brain of memory?  Paul Reber, professor of psychology at Northwestern University says that we don’t have to worry about running out of space in our brain in our lifetime. brain’s memory storage capacity to something close to around 2.5 petabytes  That’s about a million Gigabytes. Amazing isn’t it? The exact calculation of brain capacity is difficult to calculate.  We do not know how to measure the size of a memory. Certain memories involve more details and thus take up more space; other memories are forgotten and thus free up space. So it seems we can never run out of brain space for memories over our lifetime.